"Unabated, brutal, unprovoked attacks and instances of opening of fire on our innocent fishermen have been carried out by the marauding Sri Lankan Navy despite several joint statements and declarations by both the Government of India and the Government of Sri Lanka to desist from such activities," Jaya wrote in her letter to the PM dated Dec 30.

"The meek and weak response from the Government of India to the repeated instances of abduction and attacks on our fishermen in their traditional waters has emboldened the Sri Lankan Navy to act brutally against our innocent fishermen," she said.

"The continuance of such attacks and abductions will not make for a congenial atmosphere for any meaningful talks even at the level of fishermen associations of the two countries.

"Hence, I would like to reiterate that the Government of India must take a strong line and prevail upon Sri Lankan Government to end such unprovoked attacks and arrests," Jayalalithaa told Singh.

As many as 18 Indian fishermen were reportedly arrested by the Sri Lankan Navy on Monday for allegedly violating the International Maritime Boundary Line (IMBL), a day after 22 fishermen were arrested from Jagadapattinam in Pudukottai district of Tamil Nadu.

Amid an ongoing tension between India and Sri Lanka over the ethnic Tamil issue, the situation worsened with yet another case of arrest of 22 Indian fishermen from Tamil Nadu by the Sri Lankan Navy on Sunday.

Reports said 22 fishermen from Jagadapattinam in Pudukottai district of Tamil Nadu were arrested by Sri Lankan Naval personnel for allegedly fishing in their waters.

They were reportedly taken to Kangesanthurai Port in Sri Lanka.

Hundreds of Indian fishermen are already lodged in Sri Lanka jails for allegedly fishing in their waters.